Tetrahalogenated chromogenic compounds and their use

ABSTRACT

TETRAHALOGENATED CHROMOGENIC COMPOUNDS ARE DISCLOSED. ONE SUCH COMPOUND IS 3-(P-DIETHYLAMINOPHENYL)3-(1,2-DIMETHYLINDOL - 3 - YL)-4,5,6,7-TETRACHLOROPHTHALIDE. THESE COLORLESS, BUT COLORABLE DYES ARE EMPLOYED IN PRESSURE-SENSITIVE RECORD MATERIAL AND MARK-FORMING MANIFOLD SYSTEMS. THE TETRAHALOGENATED COMPOUNDS OF THIS INVENTION DEMONSTRATE GOOD FADE RESISTANCE BOTH IN RESPECT TO REFLECTIVE INTENSITY AND QUANTITY OF COLOR PRESENT.

United States Patent Office 3,136,331

Patented May 29, 1973 a C14 3,736,337 TETRAHALOGENATED CHROMOGENIC :0

COMPOUNDS AND THEIR USE Sheldon Farber, Dayton, Ohio, assignor to The National Cash Register Company, Dayton, Ohio 5 N0 Drawing. Filed Apr. 27, 1971, Ser. No. 137,952

rm. c1. C07d 5/32, 27/22, 27/56 R I US. Cl. 260-343;: 18 Claims ABSTRACT OF THE DISCLOSURE Tetrahalogenated chromogenic compounds are disclosed. One such compound is 3-(p-diethylarninophenyl)- S-(LZ-dimethylindol 3 yl)-4,5,6,7-tetrachlorophthalide. Ch

These colorless, but colorable dyes are employed in pres- =0 sure-sensitive record material and mark-forming manifold L systems. The tetrahalogenated compounds of this invention demonstrate good fade resistance both in respect 0 to reflective intensity and quantity of color present.

This invention relates to chromogenic compounds. B These chromogenic compounds are used in pressure-sensitive record material and in mark-forming manifold sys- R tems. In another aspect, this invention relates to a method R of marking on a substrate by developing dark-colored materials from these chromogenic compounds.

The chromogenic compounds of this invention have the form of substantially colorless, i.e., white, or slightly (c) colored solids, or approach being colorless when in liquid solution, but which are converted to dark-colored forms I upon reactive contact with acidic material. As used in Y mark-forming systems, marking in desired areas on support Webs or sheets is accomplished by effecting localized C reactive contact between the chromogenic compound and the acidic material on or in the web or sheet, the chromogenic compound being brought thereto by transfer, or N originally there in situ, the desired reactive contact forml R R ing dark-colored materials in the intended image-mark- R R ing areas.

Pressure-sensitive mark-forming systems of the prior art include that disclosed in application for Letters Patent ch 392,404, filed Aug. 27, 1964, now abandoned. Various c=o chromogenic compounds are disclosed in US. Pats. 3,491,- 111; 3,491,112; 3,491,116; 3,491,117; 3,509,173 and 3,509,174.

Colorless, but colorable tetrahalo chromogenic compounds now have been found. The tetrahalogenated com- R X OH pounds of this invention demonstrate good fade resist- 2 ance both in respect to reflective intensity and quantity K of color present. R OH -R Accordingly, an object of this invention is to provide tetrahalo chromogenic compounds.

Another object of this invention is to provide pressure- (9) C14 sensitive record material and mark-forming manifold systems employing these tetrahalo chromogenic compounds. 1 Still another object of this invention is to provide a 0 method of marking on a substrate by developing darkcolored materials from these tetrahalo chromogenic com- 0 pounds.

Other objects, aspects and advantages of this invention will be apparent to one skilled in the art from the follow- N ing disclosure and appended claims. B 0 R I The tetrahalo chromogenic compounds of this invention t are represented by the formula: m

pounds include:

Specific examples of these tetrahalo chromogenic com- N CH N CH3 I C2Ha N CH3 CH N (32115 l CzHs N CH3 CH E- & aHi

CzHs

and

| 3 III and the like.

Pressure-sensitive mark-forming systems provide a marking system of disposing on and/or within sheet support material the unreacted mark-forming components (at least one of which is a polymeric material) and a liquid solvent in which each of the mark-forming components is soluble, said liquid solvent being present in such form that it is maintained isolated by a pressure-rupturable barrier from at least one of the mark-forming components until the application of pressure causes a breach or rupture of the barrier in the area delineated by the pressure pattern. The mark-forming components thereby are brought into reactive contact, producing a distinctive mark.

The method of marking of this invention, i.e., by developing a dark-colored material from the substantially colorless or slightly colored chromogenic compounds comprises providing a chromogenic compound selected from among the above-mentioned compounds and bringing such chromogenic compound into reactive contact in areas where marking is desired with an acidic color-activating substance to produce a dark-colored resonant form of the chromogenic compound by the action thereon in said areas of the said acidic substance.

The acidic materials employed in this invention can be any compound within the definition of a Lewis acid, i.e., an electron acceptor. Preferably, acidic organic polymers such as phenolic polymers are employed as the acidic material. The chromogenic compounds exhibitthe advantage of improved color stability when reacted with such phenolic polymers. The solution formation of the solid particles of polymeric material in the same solvent with the substantially colorless chromogenic compounds allows penetration of the color into the support sheet, if porous, e.g., paper, so that the colored form of the chromogenic compound sinks into the body of the sheet and is not merely on the surface of the sheet. This feature protects against erasure of recorded data by attrition of the surface of the record sheet.

It is noted that the polymeric mark-forming components should have a common solubility with the chromogenic compound in at least one liquid solvent when the acid-reacting material is a phenolic or other organic acidic polymer. It is also noted that in a single system several chromogenic compounds can be used with the same or different polymeric materials. Several polymeric materials can be reactively contacted with a single chromogenic compound or with a mixture of chromogenic compounds.

As mentioned above, the solvent is maintained in physical isolation in minute droplets until such time as it is released by application of pressure. This is accomplished by several known techniques, but preferably isolation is maintained by individual encapsulation of the solvent droplets in a microcapsule according to the procedures described, for example, in US. Pat. No. 2,712,570 issued to Barrett K. Green on July 5, 1955; 2,730,457, issued to Barrett K. Green and Lowell Schleicher on Jan. 10, 1956; 2,800,457, issued to Barrett K. Green and Lowell Schleicher on July 23, 1957; and 2,800,458, issued to Barrett K. Green on July 23, 1957,

7 reissue as Re. Pat. No. 24,899 on Nov. 29, 1960. The microscopic capsules, when disposed within or upon a supporting web as a multiplicity in contiguous juxtaposition, are rupturable by pressure, such as normal marking pressures utilized, for example, in writing of typing operations.

The material or materials chosen as the wall material of the microcapsule, in addition to being pressure rupturable, must be inert with respect to the contents of the capsule and the other mark-forming components so that the wall material remains intact under normal storage conditions until such time as it is released by the application of marking pressure. Examples of such wall materials are gelatin, gum arabic and many others thoroughly described in the aforementioned patents.

For use in record material, the capsule size should not exceed 50 microns in diameter. Preferably, the capsules should be smaller than 15 microns in diameter.

The acidic polymeric material useful in this invention include phenol polymers, phenol acetylene polymers, maleic acid-rosin resins, partially or wholly hydrolyzed styrene-maleic anhydride copolymers and ethylenemaleic anhydride copolymers, carboxy polymethylene and wholly or partially hydrolyzed vinyl methyl ether maleic anhydride copolymer and mixtures thereof.

Among the phenolic polymers found useful are alkylphenol-acetylene resins, which are soluble in common organic solvents and possess permanent fusibility in the absence of being treated by cross-linking materials. A specific group of useful phenolic polymers are members of the type commonly referred to as novolacs, (as sold by Union Carbide Corp., New York, N.Y.) which are characterized by solubility in common organic solvents and which are, in the absence of cross-linking agents, permanently fusible. Generally, the phenolic polymer material found useful in practicing this invention is characterized by the presence of free hydroxyl groups and the absence of groups such as methylol, which tend to promote infusibility or cross-linking of the polymer, and by their solubility in organic solvents and relative insolubility in aqueous media. Again, obviously, mixtures of these phenol-aldehyde polymers can be employed.

Resoles, if they are still soluble, are used, though subject to change in properties upon aging.

A laboratory method useful in the selection of suitable phenolic resins is the determination of the infrared absorption pattern. It has been found that phenolic resins showing an absorption in the 3200-3500 cm? region (which is indicative of the free hydroxyl groups) and not having an absorption in the 1600-1700 cm? region are suitable. The latter absorption region is indicative of the desensitization of the hydroxyl groups and, consequently, makes such groups unavailable for reaction with the chromogenic materials.

The preparation of the phenolic formaldehyde polymeric materials for practicing this invention is described in Industrial and Engineering Chemistry, vol. 43, pp. 134 to 141, January 1951, and a particular polymer thereof is described in Example 1 of US. Pat. No. 2,052,093, issued to Herbert Honel on Aug. 25, 1936, and the preparation of the phenol-acetylene polymers is described in Industrial and Engineering Chemistry, vol. 41, pp. 73 to 77, January 1949.

The preparation of the maleic anhydride copolymers is described in the literature, such as, for example, one of the maleic anhydride vinyl copolymers, as disclosed in the publication, Vinyl and Related Polymers, by Calvin E. Schildknecht, second printing, published April 1959, by John Wiley & Sons, Incorporated. See pages 65 to 68 (styrene-maleic anhydride copolymer), 628 to 630 (vinyl methyl) ether-maleic anhydride copolymer, and 530 to 5 31 (ethylene-maleic anhydride copolymer).

When the acidic material is one of the aforementioned organic polymers, the liquid solvent chosen must be capable of dissolving the mark-forming components. The solvent can he ve atils 9r ngnq ti and a s g o multiple component solvent may be used which is wholly or partially volatile. Examples of volatile solvents useful in the aforedescribed basic chromogen-acidic polymer are toluene, petroleum, distillate, perchloroethylene, and xylene. Examples of non-volatile solvents are high-boiling point petroleum fractions and chlorinated biphenyls.

Generally, the solvent chosen should be capable of dissolving at least 0.3%, on a weight basis, of the chromogenic compound and about a 3-5 on a Weight basis, of the polymeric material to form an eflicient reaction. However, in the preferred system, the solvent should be capable of dissolving an excess of the polymeric material, so as to provide every opportunity for utilization of the chromogenic compound, and, thus, to assure the maximum coloration at a reaction site.

A further criterion of the solvent is that it must not interfere with the mark-forming reaction. In some instances, the presence of the solvent can interfere with the mark-forming reaction or diminish the intensity of the mark, in which case the solvent chosen should be sufficiently vaporizable to assure its removal from the reaction site after having, through solution, brought the markforming components into intimate admixture, so that the mark-forming contact proceeds.

Since the mark-forming reaction requires an intimate mixture of the components to be brought about through solution of said components, one or more of the markforming components can be dissolved in the isolated solvent droplets, the only requirement being that at least one of the components essential to the mark-forming reaction be maintained isolated until reactively contacted with the other.

In the usual case, the mark-forming components are so chosen as to produce a mark upon application of pressure at room temperature (20 to 25 degrees centigrade). However, the present invention includes a system in which the solvent component is not liquid at temperatures around room temperature but is liquid and in condition for forming solutions only at elevated temperatures.

The support member on which the components of the system are disposed may comprise a single or dual sheet assembly. In the case where all components are disposed on a single sheet, the record material is referred to as a self-contained system. Where there must be a migration of the solvent, with or without mark-forming component, from one sheet to another, the record material is referred to as a transfer system. (Such a system can also be referred to as a two-fold system, in that at least two sheets are required and each sheet includes a component, or components, essential to the mark-forming reaction.) Where a copious amount of the colored reaction product in liquid form is produced on a surface of one sheet, it can produce a mark by transfer to a second sheet as a colored mark.

In the preferred case, where microcapsules are employed, they can be present in the support material either disposed therethroughout or as a coating thereon, or both. The capsules can be applied to the sheet material while still dispersed in the liquid vehicle in which they were manufactured, or, if desired, separated and the separated capsules thereafter dispersed in a solution of the polymeric component (for instance, 30 grams of water and 53 grams of a 1% aqueous solution of polyvinyl methyl ether maleic anhydride) to form a coating composition in which, because of the inertness of the solution and the capsules, both retain their identity and physical integrity. When this composition is disposed as a film on the support material and dried, the capsules are held therein subject to rupture to release the liquid contained. This latter technique, relying on the incompatibility of the microcapsule and the dispersing medium of the film-forming mark-forming component, allows for a method of preparing a sensitive record coating with the capsules interspersed directly in a dry film of the polymeric material as it is aid down from he solution. A

further alternative is to disperse in a liquid medium one or more mark-forming components, insoluble therein, and disperse in said medium the insoluble microcapsules,

with the result that all components of the mark-forming system can be disposed on or within the support sheet in the one operation. Obviously, the several components can be applied individually.

The respective amounts of the several components vary, depending primarily upon the nature of the materials and the architecture of the record material unit. Suitable lower amounts include, in the case of the chromogenic material, about .005 to .075 pound per ream (a ream in this application meaning five hundred (500) sheets of 25" x 38" paper, totaling 3,300 square feet); in the case of the solvent, about 1 to. 3 pounds per ream; and in the case of the polymer, about /2 pound per ream. In all instances, the upper limit is primarily a matter of economic consideration.

In the instance where the mark-forming components are interspersed throughout a single support sheet material (so-called self-contained unit), the following technique or procedure has been found useful:

The slurry of capsules can be applied to a Wet web of paper as it exists on the screen of a Fourdrinier paper machine, so as to sink into the paper web a distance depending on the freeness of the pulp and the water content of the web at the point of application.

The capsules can be placed directly in the paper or in a support sheet. Not only capsule structures, but films which hold a multitude of droplets for local release in an area subject to pressure may be utilized. (See U.S. Pat. No. 2,299,694, which issued Oct. 20, 1942, to B. K. Green.)

With respect to the acidic organic polymeric component, a solution thereof in an evaporable solvent is introduced into twice as much Water and agitated while the evaporable solvent is blown off by an air blast. This leaves an aqueous colloidal dispersioin slurry of the polymeric material, which can be applied to the paper so as to leave a surface residue, or the slurry can be applied to paper at the size-press station of a paper-making machine by roller. In another method of making a polymersensitized sheet, the Water-insoluble polymer is ground to the desired particle size in a ball mill with water, preferably with a dispersing agent, such as a small quantity of sodium silicate. If a binder material of hydrophilic properties is ground with the phenolic material, the binder itself may act as a dispersant. If desired, an amount of binder material of up to 40%, by weight, of the employed amount of the polymeric material can be added to the ball-milled slurry of materials, such binder materials being of the paper coating binder class, including gum arabic, casein, hydroxyethylcellulose, and latex (such as styrene-butadiene copolymer). If desired, oil adsorbents in the form of fullers earth may be added to the polymeric material particles to assist in retaining, in situ, the liquid droplets to be transferred to it in data-representing configuration, for the purpose of preventing bleeding of the print.

Another way of applying the chromogenic or polymeric material individually to a single sheet of paper is by immersing a sheet of paper in a 1% to solution of the material in an evaporable solvent. Obviously, this must be done alone for each reactant, because if the other reactant material were present, it would result in a premature coloration over the sheet area. A dried sheet with one component then can be coated with a solution of the other component, the solvent of which is a nonsolvent to the already supplied component.

The polymeric material can be dissolved in ink composition vehicles to form a printing ink of colorless character and, thus, can be used to spot-print a proposed record sheet unit sensitized for recording in a reactionproduced color in those areas by application of a solution of the chromogenic material.

In the case of phenolic polymer, a printing ink can be made of up to 75% weight, of the phenolic polymeric material in a petroleum solvent to a viscosity suitable for printing purposes. The relative amounts of components to be used are the most convenient and economical amounts consistent with proper visibility of the recorded data. The resolution of the recorded data is, among other things, dependent on particle size, distribution and amount of particles, liquid solvent migration, chemical reaction efficiency, and other factors, all of which are things that can be worked out empirically by one familiar with the art, and which do not determine the principle of the invention, which, in part, involves means for enabling the bringing into solution, by marking pressure, of two normally solid components in a common liquid solvent component held isolated as liquid droplets, preferably in marking-pressure-rupturable capsules having film walls, or else held isolated in a continuous marking-pressurerupturable film as a discontinuous phase.

In the base-acid color system of this invention the acidic mark-forming component(s) reacts with the basic chromogenic material(s) to effect distinctive color formation or color change. In a multi-sheet system in which an acidic organic polymer is employed, it is desirable to include other materials to supplement the reactants. For example, kaolin can be added to improve the transfer of the liquid and/or the dissolved materials between the sheets. In addition, other materials such as bentonite, attapulgite, talc, feldspar, halloysite, magnesium trisilicate, silica gel, pyropyllite, zinc sulfide, calcium sulfate, calcium citrate, calcium phosphate, calcium fluoride, barium sulfate and tannic acid can be included.

Various methods known to the prior art and disclosed in the aforementioned application Ser. No. 392,404 to Miller et al. and U.S. Pat. application Ser. No. 420,193, now U.S. Pat. No. 3,455,721, can be employed in coating compositions of the mark-forming materials into their supporting sheets. An example of the compositions which can be coated onto the surface of an underlying sheet of a two-sheet system to react with the capsule coating on the underside of an overlying sheet is as follows:

Coating composition Percent by weight The advantages of this invention are further illustrated by the following examples. The reactants and the proportions and other specific conditions are presented as being typical and should not be construed to limit the invention unduly.

EXAMPLE I o=o 01, I

N C Hs The preparation of 3-(p dimethylaminophenyl)-3-(1- methylpyro-Z-yl) 4,5,6,7 tetrachlorophthalide was carried out by dissolving 13.5 g. of the lactol acetate of 4'-dimethylamino 3,4,5,6 tetrachloro 2 carboxybenzophenone and 2.68 g. of N-methylpyrolle in ml. of benzene. The mixture was stirred in an ice bath and A1Cl was added slowly. After 10 minutes of stirring in the ice bath, water was added. The benzene layer was separated and washed with water, with a 5% sodium bicarbonate solution and again with water. After separation, the benzene was evaporated and the product was recrystallized from a benzene-petroleum ether. The product had a M.P. of 105110 C. and a benzene solution thereof yielded a purple color on silton and a green color on kaolin.

EXAMPLE 11 C CH3 l N Cs I 3-(p-dimethylaminophenyl) 3 (2 phenylindol 3- yl)-4,5,6,7-tetrachlorophthalide was prepared by dissolving 13.5 g. of the lactol acetate of 4-dimethylamino-3,4, 5,6-tetrachloro 2 carboxybenzophenone and 6.4 g. of 2-phenylindole in 200 ml. of methylene chloride. While the mixture was being stirred on an ice bath at 5 C. 13.3 g. of AlCl was added and the temperature rose to 20 C. Water was added to the mixture after minutes of stirring. The methylene chloride layer was separated, washed with water, washed with 5% sodium bicarbonate solution, and washed again with water. After evaporation, the solid product was recrystallized from a CHC1 -petr0- leurn ether. The yield was 58% by weight and the product had a M.P. 2722.73 C. A benzene solution of the final product gave a blue color on silton and a green color on kaolin.

EXAMPLE III The following three phthalides were prepared according to the procedure described in Example II:

3-(p-dimethylaminophenyl)-3-(2-methylindo1 3 yl) 4,5, 6,7-tetrachlorophthalide;

12 3-(p-diethylaminophenyl)-3-(1,2-dimethylindol 3 yl)- 4,5,6,7-tetrachlorophthalide; and

(III) -C=O 014 i C Cga N C N CHa 3-(p-dimethylaminophenyl) 3 (1,2-dimethylindol-3- yl)4,5,6,l-tetrachlorophthalide. The three compounds were prepared from the following reactants:

(I) the laetol acetate of 4-dimethylamino-3,4,5,6-tetrachloro-2-carboxybenzophenone and Z-methylindole;

(II) 4-dimethylamino 3',4',5',6' tetrachloro-2-carboxybenzophenone and 1,2-dimethylindole; and

(III) the lactol acetate of 4-dimethylamino-3,4,5,6-tetrachloro-Z-carboxybenzophenone and 1,2-dimethylindole.

The M.P. and color on silton and kaolin paper are as yl)-4,5,6,7tetrachlorophtha1ide (II) shows an enhanced degree of fade resistance over its unchloronated analogue. The compound also demonstrates excellent solubility characteristics.

EXAMPLE IV --o=o 014 l /o o CH3 N N fi 0H8 I 3-(p-dimethylaminophenyl) 3 (l-ethyl-Lmethylindol-3-yl) 4,5,6,7 tetrachlorophthalide was prepared from a mixture of 2.0 g. of 4'-diethy1amino-3,4,5,6-tetrachioro-2-carboxybenzophenone, 2.7 g. of an 89% solution of l-ethyl-Z-methylindole and 5 ml. of acetic anhydride. The mixture was refluxed for 1 hour, cooled and poured into Water. The solution was made basic With ammonia and extracted twice with benzene. The benzene extract was washed with water, dried with Na SQ and concentrated to an oil which was crystallized from benzene to yield 2.6 g. of product with a M.P. of 200-214 C. Recrystallization from a benzene-petroleum ether yielded a M.P. of 225-227 C. A benzene solution of this material gave a blue-green color on kaolin ind a blue color on siltou sheets.

13 EXAMPLE V Cg? N g CH: N/

(II) C=O R P-Z Using the procedure described in Example 1V, 3-(p-diethylaminophenyl) 3 (1 ethyl-Z-methylindol-S-yl)- 4,5,6,7-tetrachlorophthalide was prepared from 4-diethylamino-3,4,5',6'-tetrachloro 2' carboxyphenone and 1- ethyl-Z-methylindole. Also 3-(1-ethyl-2-methylindol-3- yl)-3-(2-phenylindol-3-yl) 4,5,6,7 tetrachlorophthalide was prepared from 2-(l-ethyl-2-methylindol-3-yl)-3,4,5, 6-tetrachlorobenzoic acid and Z-phenylindole. Reflux times were 3 hours and 10 minutes, respectively.

The melting points and color on silton and kaolin papers were as follows:

3- (p-diethylaminophenyl 3 (4-N,N-benzylethyl-3-methylphenyl -4,5,6,7-tetrachl0rophthalide.

14 3-(p-diethylaminophenyl) 3 (4 N,N-dibenzylamino)- 4,5,6,7-tetrachlorophthalide.

Melting point,

C. Silton Kaolin 224-225 Green Green EXAMPLE VII m OCHsl 3 (4-diethylamino-2ethoxyphenyl)-3-(1-ethyl-2-methylindo1-3-yl)-4,5,6,7-tetrachlorophthalide was prepared by admixing 8.9 g. of 2-[l-ethyl-2-methylindo1-3-yl]-3,4,5,6- tetrachlorobenzoic acid and 4.24 g. of m-diethylaminophenetidine in 20 ml. of acetic anhydride. The mixture was refluxed 10 minutes and poured into ice water. After the addition of ammonia, the mixture was extracted with benzene. The benzene solution was washed twice with Water, dried and evaporated to a small volume. A small amount of petroleum ether was added and the resulting precipitate was collected and dried. 5.5 -g. of material was obtained, which had a M.P. of 181-182 C. After recrystallization, the M.P. was 182185 C. A benzene solution of the product gave a red-blue color when applied to silton sheets and a blue color on kaolin sheets.

EXAMPLE VIII Prints were made on sensitized sheets with Compound II of Example III and its unchloronated counterpart. The following table consists of the reflective intensities obtained on a variety of prints. R is a ratio of the intensity of color over the intensity of the background. A value of 1.000 would indicate a white color. Therefore, the less reflectance the higher the R value. If R increases with time, the print fades. Compounds which exhibit good fade resistance will demonstrate smaller increases in R with the passage of. tmie.

The reflectance values were converted to Kubelka- Munk functions (K&S), the calculations and use of which are described by Dr. G. Kortum et al. in Angewandte Chemie, International Edition, 2, pp. 333-341 (1963). These functions are a reliable measure of the quantity of color present per unit area of prints tested.

Hence, the following table provides a comparison of color intensity as well as quantity of color present.

Fresh print Print, four hours old Print, eight weeks old B K/S R me E K/S 80-20 Resin 1 0. 218 1.403 0.250 1.125 0. 310 0. 70s --C= Paraphenylphenol 0. 168 2. 060 0/168 2. 060 0. 195 1. 662 Silton 0.108 3,684 0. 225 1. 335 0. 480 0. 282 O Attapulgite 0.112 3,520 0.178 1. 898 0. 745 0. 044 C &1, g

N CH N C2Hs ([3 Unehloronated.

80-20 Resin 0. 225 1.335 0. 230 1. 289 0. 200 1. 053 --C= Paraphenylphenol 0. 143 2. 568 0. 162 2. 167 0. 172 1. 993 Oh Silt0n 0. 000 7. 303 0. 09s 4. 151 0. 025 0. 113 0 Attapulglte 0. 10s 3. 68a 0. 130 2. 911 /O Cr\ 0 /N CH N C2110 CH3 Tetraohloronated.

1 80 parts by weight paramertiary-butylphenol, and parts by weight paraphlorophenol.

Not only does the tetrachloronated compound exhibit im- (d) 01 proved reflective intensity (R) at various stages of fade, but the tetrachloronated compounds also possess increased amounts (K/ S) of color at the various stages of intensity. 0 Although this invention has been described in considerable detail, it must be understood that such detail is for R O R the purpose of illustration only and that many variations and modifications can be made by one skilled in the art /CH3 R Without departing from the scope and spirit thereof. N- --N What is claimed is: R \CHPR 1. A chromogenic compound having the formula:

(a) C14 c 3, R I \l 0 \N f R R R \N 2 OK (b) on I- I 0:0 5 \R R R -C=O N N a R R 1 (c) on --c=o N N O I; R i

s R i R R wherein each R is hydrogen, an alkyl radical having 1 to 4 carbon atoms, a phenyl radical, an alkylphenyl radical having 1 m4 carbon atoms per alkyl radical or a phenyl- 7 5 alkyl radical having 1 to 4 carbon atoms per alkyl radical.

2. A chromogenic compound according to claim I hav- 7. A chromogenic compound according to claim 1 having the formula: ing the formula:

@vijzo 5 (i=0 on? J: N CAN 8. A chromogenic compound according to claim 1 3. A chromogenic compound according to claim I havhaving the formula:

ing the formula:

C14 4 (I) Q 0 0/ CH l ll) 2 5 \N N /N N 9. A chromogenic compound according to claim 1 having the formula:

4. A chromogenic compound according to claim I having the formula: O14

. C=O Cl;

C O /O I o 0 0 0gb N CH3 CH2 C2H5 N 5 N CH3 5. A chromogenic compound according to claim lhav- 10. A chromogenic compound according to claim 1 ing the formula: having the formula:

CH3 CH3 \N I N /\N N 0%; CH3 1% C 3 JaHs 6. A chromogenic compound according to claim I hav- 0 mg the formula: 11. A chromo enic compound according to claim 1 having the formula:

CE: O l 3: is N N 3,736,337 19 20 12. A chromogenic compound according to claim 1 16. A chromogenic compound according to claim 1 having the formula: having the formula:

w il Tl) N CH: N/ /N g N C2H5 a 02115 J: 2H5

a 13. A chromogenic compound according to claim 1 5 17. A chromogenic compound according to claim 1 having the formula? having the formula:

(L m E l in 18. A chromogcnic compound according to claim 1 14. A chromogenic compound according to claim 1 having the formula:

having the formula: C1 on 4 --o=0 0:0 I 0 (1 CH; o

ll CzHs CHI-Q \N/ CH N N I 3 N (32116 C a OzHi 15. A chromogenic compound according to claim 1 having the formula? 0:0 References Cited UNITED STATES PATENTS 0 3,035,021 5/1962 Howe 26047 JOSEPH A. NARCAVAGE, Primary Examiner 50 H 52g Q US. (:1. X.R. 0241: 117-35.6, 36.2, 36.9; 260-3263, 326.14 R 

